Syyeduna Abu-Hurayrah Radi Allahu Anho narrates that Syyeduna Rasulullah Sallal lahu alaihi wa sallam said: "Without a doubt Allah will send at the beginning of every century such a person for this Ummah who will renew and restore their religion (Deen)."(Narrated by Imam Abu-Dawood, and Imam Hakim in his Mustadrak, Imam Bayhaqee in his Al-Ma'rifah, Imam Jalal al-Deen Suyootee in al-Jama'e al-Sagheer fi Hadith al-Basheer wal-Nazeer, Imam Bayhaqee in Al-Mudkhal and Imam Hasan bin Sufyan and Imam Bazar in their Musnads, Imam Tabranee in his al-Mu'jam al-al-Awsat, Imam Ibn 'Adee in his Kamil and Imam Abu-Na'eem in his al-Hil'ya)In other the words, when there comes a period in which there is a shortage of knowledge and corruption in following of the Sunnah; when there is an increase in false innovations and ignorance; then Allah will send a person at the beginning or end of every century who will show the difference between Sunnah and Bid'at. He will refuse and destroy false innovations and will fear none but Allah. He will very bravely and sincerely raise the flag of Deen-e-Muhammadi (Sallal lahu alaihi wa sallam). This person is known as a "Mujaddid.”The author of the book, "Siraj al-Munir Sharh Jame'h al-Saghir", has explained who a Mujaddid is in the following words:"In other words, to revive the Deen is to revive those teachings of the Quran and Sunnah that are being destroyed and to give command according to the Quran and Sunnah."Allamah Munaadi (Alaihir rahma) states:

"A Mujaddid is one who separates Sunnah from Bid'ah and one who degrades the status of the Ahle Bid'ah."

The correct meaning or concept of Tajdeed (Revival) is that one or more qualities are found in a person through which Ummat-e-Muhammadiyya benefit religiously for example teaching Islamic education, lecturing, spreading, informing about Islam and forbidding people of evil and assisting the truthful.

It is not necessary that a Mujaddid be from the Ahle-Bayt as claimed by the Shias and other groups.

It is not necessary that a Mujaddid be a Mujtahid.

What is absolutely necessary is that he be a Sunni with correct beliefs according to the Ahle-Sunnah wa Jamah.

He is a profound Aalim e Deen.

He is a master of most of the Sciences of Knowledge.

He is an outstanding Scholar of his time.

His services for Deen be purely for the pleasure of Allah and His Rasool and not for worldly gain.

He is fearless of opposition and rulers of his time.

He will not act or give verdicts to please any person besides Allah and His Rasool.

He will not fear speaking or supporting truth in all circumstances.

He will not use religion to gain worldly fame.

He will be a very pious person.

He will perfect mixture of the Shari'ah and Tari'qah.

He will not tolerate any opposition to the Shari'ah.

And according to Allama Imam Isma'il Haqqee, it is necessary for a Mujaddid that both in the last portion of the century he was born in and the beginning of the century he passes away in, he be famous and be a fountain and focal authority of religion for the Ulama of his time.

It is also necessary for a Mujaddid that the Scholars (Ulama) of his time observe, benefit and be convinced of his impeccable lifestyle and profound knowledge and hence acknowledge and announce in public that he is a Mujaddid.

Therefore it is important that a Mujaddid be a perfect Alim of both the external (Shari'ah) and internal (Spiritual) sciences of knowledge promoting the protection the Sunnah and fighting and destroying Bid'ah.

"A Mujaddid is recognized by the strong opinion of his contemporary noble Ulama who greatly benefit from his condition and abundant Knowledge. He will be an embodiment of both external and internal sciences of knowledge supporting and defending the Sunnah and challenging and defeating Bid'ah."Can their be more than one Mujaddid to a century?

There can be more, and there has already been more than one Mujaddid to a Century. In the Hadith, the Arabic word that is used to explain the coming of the Mujaddid is in the singular tense, but according to the meaning, it is a plural as it has been explained in the Kitaabs of Usool-e-Fiqh. Allamah Mulla Ali bin Sultan Qaari (Alaihir rahmah) who is also said to be the Mujaddid of the 11th Century says,"From the words, not only one single person is implied, but the implication is towards a group of people, from amongst whom each one is reforming a single type of knowledge or all types of knowledge in his city."

So, sometimes a single Mujaddid is born in a century and sometimes there are two or a group in one given century when a agreement cannot be reached on one person. There are times when an Alim is in the middle of the century who may be more knowledgeable and excellent than the Mujaddid, but he will not be classified as a Mujaddid because he did not get the early stages of the century. This is because generally when the century ends many of the great Ulama also pass away and great conflict and Fitna engulfs the Ummah. Bid'ah and religious corruption creeps into the masses that tend to deviate from the pure teachings of Islam. At this crucial period there is a great need for revival in matters of Deen. At this critical time Allah sends such an Aalim who removes all evil and religious corruption from the Ummah by publicly announcing and refusing them. He will be the best of people among the dignitaries of his time.